Children with meningomyelocele (MMC) almost always have associated Arnold Chiari malformations of the brainstem, with resultant compression of brainstem ventilatory control centers. As a result, infants with MMC have an increased incidence of central apnea and central hypoventilation. This abnormal central control of ventilation is a possible mechanism for the increased death rate in this population. However, no studies have evaluated patients older than infancy for clinical evidence of pathologic central apnea, or for evidence of obstructive sleep apnea. We therefore plan to perform clinical evaluations and polysomnography in all patients, regardless of symptoms, who are being followed at the Spina Bifida clinic. To date, one patient has been evaluated; this patient's polysomnogram was normal.